diff --git a/flang/lib/Frontend/CompilerInvocation.cpp b/flang/lib/Frontend/CompilerInvocation.cpp
--- a/flang/lib/Frontend/CompilerInvocation.cpp
+++ b/flang/lib/Frontend/CompilerInvocation.cpp
@@ -605,16 +605,16 @@
       if (wArg == "error") {
         res.setWarnAsErr(true);
       } else if (wArg == "extra") {
-        const unsigned id = diags.getCustomDiagID(
+        const unsigned diagID = diags.getCustomDiagID(
             clang::DiagnosticsEngine::Warning,
             "Argument `-Wextra` was ignored during compilation. Only `-Werror` "
             "is supported currently.");
-        diags.Report(id);
+        diags.Report(diagID);
       } else {
-        const unsigned id =
+        const unsigned diagID =
             diags.getCustomDiagID(clang::DiagnosticsEngine::Error,
                                   "Only `-Werror` is supported currently.");
-        diags.Report(id);
+        diags.Report(diagID);
         break;
       }
     }
diff --git a/flang/test/Driver/werror-all.f90 b/flang/test/Driver/werror-all.f90
new file mode 100644
--- /dev/null
+++ b/flang/test/Driver/werror-all.f90
@@ -0,0 +1,11 @@
+! Ensures that -Werror is read regardless of whether or not other -W
+! flags are present in the CLI args
+
+! RUN: not %flang -std=f2018 -Werror -Wextra %s 
+! RUN: %flang -std=f2018 -Wextra -Wall %s
+
+program werror_check_all
+  integer :: a(3)
+  forall (j=1:n) a(i) = 1
+end program werror_check_all
+
diff --git a/flang/test/Driver/wextra-ok.f90 b/flang/test/Driver/wextra-ok.f90
new file mode 100644
--- /dev/null
+++ b/flang/test/Driver/wextra-ok.f90
@@ -0,0 +1,7 @@
+! Ensure that supplying -Wextra into flang-new does not raise error
+
+! RUN: %flang -std=f2018 -Wextra %s
+! RUN: not %flang -std=f2018 -Wblah -Wextra %s
+
+program wextra_ok
+end program wextra_ok